Reversing linkage

ABSTRACT

A linkage mechanism comprising a moveable member mounted for movement with respect to a fixed member to which it is connected. The moveable member is provided with first and second elements spaced from each other with one element constituting a moveable element while the other constitutes a datum element. The relative movement between the moveable member and the fixed member is achieved by means which are located and arranged to preferentially utilise the first of the spaced elements as the datum with respect to which the second element is moved. The mechanism further comprises a means for selectively inhibiting movement of the second element which is preferably electrically controlled, whereby to cause the second element to become the datum. The linkage mechanism may be utilised in a door lock.

The present invention relates to a reversing linkage and moreparticularly to an electrically controlled reversing linkage. By areversing linkage we mean a linkage in which input motion in a firstdirection will result in output motion in either the first direction ora second opposite direction.

It is an object of the present invention to provide a reversing linkagewhich is simple to construct, reliable in operation and can be readilycontrolled.

Accordingly, the present invention provides a linkage mechanismcomprising:

a moveable member mounted for movement with respect to a fixed member towhich it is connected and which constrains movement of the moveablemember, the moveable member being provided with first and secondelements spaced form each other and one of which constitutes a moveableelement while the other constitutes a datum element;

means for causing relative movement between the moveable member and thefixed member, said means being located and arranged whereby topreferentially utilise the first of the spaced elements as the datumwith respect to which the second element is moved; and

means for selectively inhibiting movement of said second element wherebyto cause the second element to become the datum with respect to whichthe first element is moved.

Such a linkage has a large variety of uses and, for example, could beused in the high speed yarn transfer system disclosed in our earlierco-pending UK Application No 0122406.2 or in the lock mechanismdisclosed in our earlier co-pending UK Application No 0208508.2.

In order that the present invention be more readily understood, anembodiment thereof will now be described by way of example withreference to the accompanying drawings, in which:—

FIG. 1 is an exploded perspective view of a reversing linkage accordingto the present invention;

FIG. 2 is a front view of the linkage of FIG. 1 in a first condition;

FIG. 3 is a front view of the linkage of FIG. 1 in a second condition;and

FIG. 4 is a front view of the linkage of FIG. 1 in a third condition.

A preferred embodiment will now be described as a “smart” lock ie onewhich requires both mechanical and electrical actuation before it willoperate. This is but one use of the linkage, which with minoralterations could be used for a number of purposes.

Referring now to FIG. 1, this shows an exploded perspective view of apart of a door lock. It comprises a base member 10 provided with a base11 which reviews a one end of barrel 12. The other end of the barrel isprovided with an actuator pin 14 which is provided at a position whichis radially offset from the axis of rotation of the barrel 12.

The pin 14 is received in a slot 16 in a link arm 17. The slot ispositioned at a suitable location in the arm 17 depending on the designof the lock and the forces required but in this case it is generally,centrally located between two pins 18 and 19. In this case, the pin 19is longer than the pin 18 but this need not be the case and will againdepend on the exact design of the remainder of the lock.

The pins 18,19 on the link arm 17 are received in respective slots 20,21in a face-plate 24 which is fixed on the base member 10. The slot 20 isprovided with a cross-slot 22 whose purpose will be explained later.

Although not shown in the Figure, the base member 10 is fixed andreceives the faceplate 24. The shape of the faceplate is such that thefaceplate remains fixed with the base member even when movement of thebarrel 12 and link arm 17 occurs. The link arm is preferably arrangedbetween the base 11 of the base member 12 and the faceplate 24.

Turning now to FIG. 2, this shows the lock of FIG. 1 in an assembledcondition and the same reference numerals are used for the same part.FIG. 2 shows the device at rest in its datum position with the pin 19biased to the position shown by a spring between the pin 14 on thebarrel 12 and the pin 19.

An electrically operated device such as a piezo electric actuator sitsabove the mechanism and is arranged such that it will cause insertioninto and rejection from the cross-slot 22 of a blocking member 23. Themember is a good fit into the cross-slot 22 and interferes with itsmovement of the pin 18 away from its rest position as shown in FIG. 2.

In FIG. 3, again the same parts use the same reference numerals but herethe barrel 12 has been rotated in a clockwise direction. This has causedthe link arm 17 to pivot in a clockwise direction about the pin 19 whichin turn has caused the pin 18 to rise in the slot 20 in view of the factthat there is no blocking member in the cross-slot 22. Thus, if the pin19 is used as an output member for the lock, rotation of the barrel 12has not resulted in any movement of the pin 19.

However, if the blocking member is present in the cross-slot 22,movement of the pin 18 in the slot 20 is inhibited and so rotation ofthe barrel 12 in a clockwise direction will result in the link arm beingforced to pivot in an anti-clockwise direction to raise the pin 19 inthe slot 21 as shown in FIG. 4.

The slots 20,21 of the face plate 24 are shown in the diagram as arcuatein shape. However, the slots may be linear and may also be of any lengthand width. Additionally, the slots 20,21 do not necessarily have to beof the same dimensions.

In addition, the Figures show the movement of the actuator pin to moveto approximately 45° from the datum position. However, the mechanism isnot limited to such motion and the degree of radial movement mayincrease or decrease. For example, complete reciprocation of pin 18within the slot 20 may be possible if the degree of rotation of thebarrel 12 is increased.

In the above described preferred embodiment, the faceplate 24 receivesthe actuator pin 14 of the barrel 12 in an opening which is shaped suchas to allow a certain degree of radial movement of the actuator pin withrespect to the opening. It will be appreciated that the shape of theopening is not limited to that shown in the Figures and that anysuitable opening may be utilised which allows the mechanism to operateto produce the desired result. In particular, the opening may be in theshape of a groove which receives the actuator pin 14 and constrains themovement of the pin.

It will be appreciated that other various modifications may be made tothe above mechanism. For example, the pin 18 as well as the pin 19 couldbe used as an output which would mean that motion in one direction ofthe barrel 12 could be translated into motion in one or other directiondepending on the state of actuation of the electrically operated device.Also, the barrel could be replaced by a slider such as might be used ina locking bolt or by a cam that is connected to a key barrel thusproviding a lock that requires both a mechanical key and an electronicsignal to operated.

1. A linkage mechanism comprising: a moveable member mounted formovement with respect to a fixed member to which it is connected andwhich constrains movement of the moveable member, the moveable memberbeing provided with first and second elements spaced from each other andone of which constitutes a moveable element while the other constitutesa datum element; means for causing relative movement between themoveable member and the fixed member, said means being located andarranged whereby to preferentially utilise the first of the spacedelements as the datum with respect to which the second element is moved;and means for selectively inhibiting movement of said second elementwhereby to cause the second element to become the datum with respect towhich the first element is moved.
 2. The linkage mechanism according toclaim 1 wherein the means for utilising relative movement includes anarcuately moveable member.
 3. The linkage mechanism according to claim 2wherein the fixed member is arranged to constrain movement of the spacedelements by receiving them in slots or grooves.
 4. The linkage mechanismaccording to claim 3 wherein the slots or grooves are arcuate.
 5. Thelinkage mechanism according to claim 4 wherein the means for selectivelyinhibiting movement is electrically controlled.
 6. The linkage mechanismaccording to claim 1 wherein the means for selectively inhibitingmovement includes a piezo-electric actuator.
 7. (canceled)
 8. A doorlock utilising the linkage mechanism according to claim
 1. 9. Thelinkage mechanism according to claim 1 wherein the fixed member isarranged to constrain movement of the spaced elements by receiving themin slots or grooves.
 10. The linkage mechanism according to claim 9wherein the slots or grooves are arcuate.
 11. The linkage mechanismaccording to claim 1 wherein the means for selectively inhibitingmovement is electrically controlled.